1.3.3 Power Supply Selection

Posted by JTSF at Saturday, May 25, 2013 Read our previous post

How much power does your NAS need? Let's compute the maximum power consumption required. You can also use this utility as a guide.

QTY	Component	Estimated Power Consumption
1	ECS NM70-I2 (V1.0)	20W
1	Kingston DDR3 8GB	3W
6	2TB HDD (5400RPM)	20W* x 6 = 120W
1	120mm enclosure fan	4W
Maximum power load		147W

*20W is the power drawn during bootup; figure is taken from here

Notice I included 6 HDDs in the calculation. For scalability, the power supply must be capable of supporting the maximum number of HDDs you install on your NAS plus the underlying backbone. With the above figure, I will need a power supply that is between 150W - 200W.

PicoPSU?
My inital plan is just to get any cheap power supply for the NAS. When Mast C (my gang) suggested PicoPSU, I have lots of doubts on this tiny little piece of PCB with capacitors:

1. Will this tiny fellow even work?
2. Does it have enough juice to power my NAS?
3. Is it compatible with Mini-ITX motherboards?
4. How reliable it is? Will it overheat or kill my parts?

I did some studies and found them widely used in HTPC and NAS setups. Below are some links for reference:
VR-Zone forum - PICO PSU Anyone?
FreeNAS forum - Discussion on Pico-PSU
Whirlpool forum - NAS setup with PicoPsu
PicoPSU used in project - Data_Center_In_A_Box
A blogger using it since 2006

The efficient power consumption and the tiny size of the PicoPSU appealed to my NAS build. Recall that I faced a challenging task to compete with Synology 15W power consumption at idle. Any methods to lower the power consumption of my build are most welcomed. Moreover, the tiny size of the PicoPSU grants me the freedom to use any small enclosure. I also fancy the idea of silent PSU and lowered heat dissipation. Great! 


130W PicoPSU Bundle
Out on a search again, I found this thread at VR-Zone and went on to scrutinize the PicoPSU seller with lots of questions. The neat bundle is a 130W PicoPSU paired up with a Dell 150W power adapter. After careful consideration, I decided to take a bet for $75. If it is not compatible with my build, the backup plan is to sell it off and get a normal PSU. $193 left, let's head straight onto the last two selections, HDDs & the enclosure. =)